Commit 954c0b7c authored Aug 22, 2006 by Daniel Ritz Committed by Greg Kroah-Hartman Aug 26, 2006

[PATCH] PCI: use PCBIOS as last fallback



there was a change in 2.6.17 which affected the order in which the PCI
access methods are probed.  this gives regressions on some machines with
broken BIOS.  the problem is that PCBIOS sometimes reports last bus wrong,
leaving cardbus non-funcational.  previously those system worked fine with
direct access.

The patch changes the PCI init code to have PCBIOS as last fallback, yet
the PCBIOS code still has to run first to set pcibios_last_bus to the value
reported by the BIOS.  this is needed in case legacy PCI probing
(arch/i386/pci/legacy.c) is used to detect peer busses.  using direct
access if available fixes the cardbus problems.

Signed-off-by: Daniel Ritz <daniel.ritz@gmx.ch>
Cc: Dave Hansen <haveblue@us.ibm.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

parent faf9b616

arch/i386/pci/init.c

+6 −2

Original line number	Diff line number	Diff line
		@@ -14,8 +14,12 @@ static __init int pci_access_init(void)
		#ifdef CONFIG_PCI_BIOS
		pci_pcbios_init();
		#endif
		if (raw_pci_ops)
		return 0;
		/*
		* don't check for raw_pci_ops here because we want pcbios as last
		* fallback, yet it's needed to run first to set pcibios_last_bus
		* in case legacy PCI probing is used. otherwise detecting peer busses
		* fails.
		*/
		#ifdef CONFIG_PCI_DIRECT
		pci_direct_init();
		#endif